In a large-scale ground power station, a container-type inverter device with a power higher than 1 MW is adopted usually. More than two high power inverters (with a power higher than 500 kW) are integrated in the container to form a central inverter device, which has advantages of easy installation, easy maintenance, small occupation, low cost and the like. Alternatively, in a large-scale ground power station, the high power inverter is directly made into an outdoor cabinet to form a single inverter device with a power higher than 1 MW. However, these two types of inverter device have a small amount of MPPTs (generally 2 to 4 MPPTs) due to design limitations, which cannot meet a requirement of multiple MPPT control for complex terrain. Thus energy yield is greatly affected.